Hi Mike thanks for suggestions. I previously did use the 24v cut off method you mention at one point, but currently the opensprinkler is also controlling the zones that would refill each tank with a float valve. My goal is to not have to conciously know that the res has emptied and its time to refill, as much as I want a push / email letting me know the tank has been refilled and its time to show up and mix nutrients and ph. the tanks are 50-250 gallons so the liquid measuring tape wont help me much there. Appreciate the thoughts though!
Still trying to find out why OSPI is having issues with http stations and the on/off statements being garbled.